BACKGROUND Perianal manifestations occur in almost half of patients with Crohn's disease and often respond poorly to conventional therapies. The introduction of anti-tumour necrosis factor alpha agents (e.g. infliximab) has altered the management of patients who fail first and second line medical and surgical therapies. METHODS We performed a literature search of the PubMed database using the Medical Search Headings infliximab, perianal Crohn's disease, fistulae, cost and safety. We also performed a manual search using references from these articles, review articles and proceedings from major gastroenterology meetings. RESULTS Use of infliximab, at a dose of 5mg/kg at intervals of 0, 2 and 6 weeks, results in significant improvement in disease in approximately 70% of patients with fistulae. Prior examination under anaesthesia with placement of non-cutting seton sutures in fistula tracks is a useful adjunct in many patients. Preliminary results show a benefit from maintenance infliximab therapy and from concomitant use of immunosuppressants such as azathioprine. No clinical or biochemical markers have been identified which predict non-response to infliximab, although its use is contraindicated in patients with strictures. Acute infusion reactions are the most common side-effect of infliximab therapy and they are usually mild. Despite initial fears, the incidence of opportunistic infection is low. There is inadequate information, at present, regarding a possible increase in incidence of lymphoma with infliximab therapy. Infliximab is expensive compared with established therapies and its use will increase the lifetime cost of treating Crohn's disease. CONCLUSIONS While infliximab is a useful adjunct in selected patients, the cornerstones of management of perianal Crohn's are essentially unchanged.